Rotating separator with housing preventing separated liquid carryover

ABSTRACT

A rotating separator has a housing preventing separated liquid carryover. A plenum between the annular rotating separating filter element and the housing sidewall has one or more flow path separating guides minimizing the flow of separated liquid to the outlet. The flow path guides may include one or more fins and/or swirl flow dampers and/or a configured surface.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of and claims priority to U.S.patent application Ser. No. 14/880,003, entitled “ROTATING SEPARATORWITH HOUSING PREVENTING SEPARATED LIQUID CARRYOVER,” filed on Oct. 9,2015, which is a continuation of and claims priority to U.S. patentapplication Ser. No. 13/664,025, entitled “ROTATING SEPARATOR WITHHOUSING PREVENTING SEPARATED LIQUID CARRYOVER,” filed on Oct. 30, 2012,which has granted as U.S. Pat. No. 9,194,265, which claims the benefitof and priority from Provisional U.S. Patent Application No. 61/555,529,filed Nov. 4, 2011, all of which are incorporated by reference in theirentireties and for all purposes. U.S. patent application Ser. No.13/664,025 is a continuation-in-part of U.S. patent application Ser. No.12/969,742, filed Dec. 16, 2010, now U.S. Pat. No. 8,794,222, and U.S.patent application Ser. No. 12/969,755, filed Dec. 16, 2010, now U.S.Pat. No. 8,807,097. U.S. patent application Ser. Nos. 12/969,742 and12/969,755 claim the benefit of and priority from Provisional U.S.Patent Application No. 61/298,630, filed Jan. 27, 2010, Provisional U.S.Patent Application No. 61/298,635, filed Jan. 27, 2010, Provisional U.S.Patent Application No. 61/359,192, filed Jun. 28, 2010, Provisional U.S.Patent Application No. 61/383,787, filed Sep. 17, 2010, Provisional U.S.Patent Application No. 61/383,790, filed Sep. 17, 2010, and ProvisionalU.S. Patent Application No. 61/383,793, filed Sep. 17, 2010. All of theabove applications are hereby incorporated herein by reference.

BACKGROUND AND SUMMARY Parent Applications

The noted parent '742 and '755 applications relate to internalcombustion engine crankcase ventilation separators, particularlycoalescers. Internal combustion engine crankcase ventilation separatorsare known in the prior art. One type of separator uses inertialimpaction air-oil separation for removing oil particles from thecrankcase blowby gas or aerosol by accelerating the blowby gas stream tohigh velocities through nozzles or orifices and directing same againstan impactor, causing a sharp directional change effecting the oilseparation. Another type of separator uses coalescence in a coalescingfilter for removing oil droplets. The inventions of the parent '742 and'755 applications arose during continuing development efforts in thelatter noted air-oil separation technology, namely removal of oil fromthe crankcase blowby gas stream by coalescence using a coalescingfilter.

Present Application

The present disclosure arose during continuing development efforts inseparating liquid from a fluid mixture, including the above notedtechnology, and including a rotating separator separating liquid from afluid mixture, including air-oil and other liquid-fluid mixtures.

In one embodiment, the present disclosure provides a housing for anannular rotating separating filter element, which housing preventsseparated liquid carryover.

BRIEF DESCRIPTION OF THE DRAWINGS Parent Applications

FIGS. 1-21 are taken from parent U.S. patent application Ser. No.12/969,742.

FIG. 1 is a sectional view of a coalescing filter assembly.

FIG. 2 is a sectional view of another coalescing filter assembly.

FIG. 3 shows another embodiment for a drive mechanism.

FIG. 4 is a sectional view of another coalescing filter assembly.

FIG. 5 is a schematic view illustrating operation of the assembly ofFIG. 4.

FIG. 6 is a schematic system diagram illustrating an engine intakesystem.

FIG. 7 is a schematic diagram illustrating a control option for thesystem of FIG. 6.

FIG. 8 is a flow diagram illustrating an operational control for thesystem of FIG. 6.

FIG. 9 is like FIG. 8 and shows another embodiment.

FIG. 10 is a schematic sectional view show a coalescing filter assembly.

FIG. 11 is an enlarged view of a portion of FIG. 10.

FIG. 12 is a schematic sectional view of a coalescing filter assembly.

FIG. 13 is a schematic sectional view of a coalescing filter assembly.

FIG. 14 is a schematic sectional view of a coalescing filter assembly.

FIG. 15 is a schematic sectional view of a coalescing filter assembly.

FIG. 16 is a schematic sectional view of a coalescing filter assembly.

FIG. 17 is a schematic view of a coalescing filter assembly.

FIG. 18 is a schematic sectional view of a coalescing filter assembly.

FIG. 19 is a schematic diagram illustrating a control system.

FIG. 20 is a schematic diagram illustrating a control system.

FIG. 21 is a schematic diagram illustrating a control system.

Present Application

FIG. 22 is a sectional view taken into the page of FIG. 1 and showingsimilar structure as in FIG. 1 but modified in accordance with thepresent disclosure.

FIG. 23 is an enlarged view of a portion of FIG. 22.

FIG. 24 is a view like a portion of FIG. 14.

FIG. 25 is an enlarged view of a portion of FIG. 24.

FIG. 26 is a perspective view of a portion of the sidewall structure ofFIG. 22 and showing an alternate embodiment.

FIG. 27 is like FIG. 26 and shows another embodiment.

FIG. 28 is like FIG. 24 and shows another embodiment.

FIG. 29 is like FIG. 24 and shows another embodiment.

FIG. 30 is like FIG. 24 and shows another embodiment.

DETAILED DESCRIPTION Parent Applications

The following description of FIGS. 1-21 is taken from commonly ownedco-pending parent U.S. patent application Ser. No. 12/969,742, filedDec. 16, 2010, which shares a common specification with commonly ownedco-pending parent U.S. patent application Ser. No. 12/969,755, filedDec. 16, 2010.

FIG. 1 shows an internal combustion engine crankcase ventilationrotating coalescer 20 separating air from oil in blowby gas 22 fromengine crankcase 24. A coalescing filter assembly 26 includes an annularrotating coalescing filter element 28 having an inner periphery 30defining a hollow interior 32, and an outer periphery 34 defining anexterior 36. An inlet port 38 supplies blowby gas 22 from crankcase 24to hollow interior 32 as shown at arrows 40. An outlet port 42 deliverscleaned separated air from the noted exterior zone 36 as shown at arrows44. The direction of blowby gas flow is inside-out, namely radiallyoutwardly from hollow interior 32 to exterior 36 as shown at arrows 46.Oil in the blowby gas is forced radially outwardly from inner periphery30 by centrifugal force, to reduce clogging of the coalescing filterelement 28 otherwise caused by oil sitting on inner periphery 30. Thisalso opens more area of the coalescing filter element to flow-through,whereby to reduce restriction and pressure drop. Centrifugal forcedrives oil radially outwardly from inner periphery 30 to outer periphery34 to clear a greater volume of coalescing filter element 28 open toflow-through, to increase coalescing capacity. Separated oil drains fromouter periphery 34. Drain port 48 communicates with exterior 36 anddrains separated oil from outer periphery 34 as shown at arrow 50, whichoil may then be returned to the engine crankcase as shown at arrow 52from drain 54.

Centrifugal force pumps blowby gas from the crankcase to hollow interior32. The pumping of blowby gas from the crankcase to hollow interior 32increases with increasing speed of rotation of coalescing filter element28. The increased pumping of blowby gas 22 from crankcase 24 to hollowinterior 32 reduces restriction across coalescing filter element 28. Inone embodiment, a set of vanes may be provided in hollow interior 32 asshown in dashed line at 56, enhancing the noted pumping. The notedcentrifugal force creates a reduced pressure zone in hollow interior 32,which reduced pressure zone sucks blowby gas 22 from crankcase 24.

In one embodiment, coalescing filter element 28 is driven to rotate by amechanical coupling to a component of the engine, e.g. axially extendingshaft 58 connected to a gear or drive pulley of the engine. In anotherembodiment, coalescing filter element 28 is driven to rotate by a fluidmotor, e.g. a pelton or turbine drive wheel 60, FIG. 2, driven by pumpedpressurized oil from the engine oil pump 62 and returning same to enginecrankcase sump 64. FIG. 2 uses like reference numerals from FIG. 1 whereappropriate to facilitate understanding. Separated cleaned air issupplied through pressure responsive valve 66 to outlet 68 which is analternate outlet to that shown at 42 in FIG. 1. In another embodiment,coalescing filter element 28 is driven to rotate by an electric motor70, FIG. 3, having a drive output rotary shaft 72 coupled to shaft 58.In another embodiment, coalescing filter element 28 is driven to rotateby magnetic coupling to a component of the engine, FIGS. 4, 5. An enginedriven rotating gear 74 has a plurality of magnets such as 76 spacedaround the periphery thereof and magnetically coupling to a plurality ofmagnets 78 spaced around inner periphery 30 of the coalescing filterelement such that as gear or driving wheel 74 rotates, magnets 76 movepast, FIG. 5, and magnetically couple with magnets 78, to in turn rotatethe coalescing filter element as a driven member. In FIG. 4, separatedcleaned air flows from exterior zone 36 through channel 80 to outlet 82,which is an alternate cleaned air outlet to that shown at 42 in FIG. 1.The arrangement in FIG. 5 provides a gearing-up effect to rotate thecoalescing filter assembly at a greater rotational speed (higher angularvelocity) than driving gear or wheel 74, e.g. where it is desired toprovide a higher rotational speed of the coalescing filter element.

Pressure drop across coalescing filter element 28 decreases withincreasing rotational speed of the coalescing filter element. Oilsaturation of coalescing filter element 28 decreases with increasingrotational speed of the coalescing filter element. Oil drains from outerperiphery 34, and the amount of oil drained increases with increasingrotational speed of coalescing filter element 28. Oil particle settlingvelocity in coalescing filter element 28 acts in the same direction asthe direction of air flow through the coalescing filter element. Thenoted same direction enhances capture and coalescence of oil particlesby the coalescing filter element.

The system provides a method for separating air from oil in internalcombustion engine crankcase ventilation blowby gas by introducing a Gforce in coalescing filter element 28 to cause increased gravitationalsettling in the coalescing filter element, to improve particle captureand coalescence of submicron oil particles by the coalescing filterelement. The method includes providing an annular coalescing filterelement 28, rotating the coalescing filter element, and providinginside-out flow through the rotating coalescing filter element.

The system provides a method for reducing crankcase pressure in aninternal combustion engine crankcase generating blowby gas. The methodincludes providing a crankcase ventilation system including a coalescingfilter element 28 separating oil from air in the blowby gas, providingthe coalescing filter element as an annular element having a hollowinterior 32, supplying the blowby gas to the hollow interior, androtating the coalescing filter element to pump blowby gas out ofcrankcase 24 and into hollow interior 32 due to centrifugal forceforcing the blowby gas to flow radially outwardly as shown at arrows 46through coalescing filter element 28, which pumping effects reducedpressure in crankcase 24.

One type of internal combustion engine crankcase ventilation systemprovides open crankcase ventilation (OCV), wherein the cleaned airseparated from the blowby gas is discharged to the atmosphere. Anothertype of internal combustion crankcase ventilation system involves closedcrankcase ventilation (CCV), wherein the cleaned air separated from theblowby gas is returned to the engine, e.g. is returned to the combustionair intake system to be mixed with the incoming combustion air suppliedto the engine.

FIG. 6 shows a closed crankcase ventilation (CCV) system 100 for aninternal combustion engine 102 generating blowby gas 104 in a crankcase106. The system includes an air intake duct 108 supplying combustion airto the engine, and a return duct 110 having a first segment 112supplying the blowby gas from the crankcase to air-oil coalescer 114 toclean the blowby gas by coalescing oil therefrom and outputting cleanedair at output 116, which may be outlet 42 of FIG. 1, 68 of FIG. 2, 82 ofFIG. 4. Return duct 110 includes a second segment 118 supplying thecleaned air from coalescer 114 to air intake duct 108 to join thecombustion air being supplied to the engine. Coalescer 114 is variablycontrolled according to a given condition of the engine, to bedescribed.

Coalescer 114 has a variable efficiency variably controlled according toa given condition of the engine. In one embodiment, coalescer 114 is arotating coalescer, as above, and the speed of rotation of the coalesceris varied according to the given condition of the engine. In oneembodiment, the given condition is engine speed. In one embodiment, thecoalescer is driven to rotate by an electric motor, e.g. 70, FIG. 3. Inone embodiment, the electric motor is a variable speed electric motor tovary the speed of rotation of the coalescer. In another embodiment, thecoalescer is hydraulically driven to rotate, e.g. FIG. 2. In oneembodiment, the speed of rotation of the coalescer is hydraulicallyvaried. In this embodiment, the engine oil pump 62, FIGS. 2, 7, suppliespressurized oil through a plurality of parallel shut-off valves such as120, 122, 124 which are controlled between closed and open or partiallyopen states by the electronic control module (ECM) 126 of the engine,for flow through respective parallel orifices or nozzles 128, 130, 132to controllably increase or decrease the amount of pressurized oilsupplied against pelton or turbine wheel 60, to in turn controllablyvary the speed of rotation of shaft 58 and coalescing filter element 28.

In one embodiment, a turbocharger system 140, FIG. 6, is provided forthe internal combustion engine 102 generating blowby gas 104 incrankcase 106. The system includes the noted air intake duct 108 havinga first segment 142 supplying combustion air to a turbocharger 144, anda second segment 146 supplying turbocharged combustion air fromturbocharger 144 to engine 102. Return duct 110 has the noted firstsegment 112 supplying the blowby gas 104 from crankcase 106 to air-oilcoalescer 114 to clean the blowby gas by coalescing oil therefrom andoutputting cleaned air at 116. The return duct has the noted secondsegment 118 supplying cleaned air from coalescer 114 to first segment142 of air intake duct 108 to join combustion air supplied toturbocharger 144. Coalescer 114 is variably controlled according to agiven condition of at least one of turbocharger 144 and engine 102. Inone embodiment, the given condition is a condition of the turbocharger.In a further embodiment, the coalescer is a rotating coalescer, asabove, and the speed of rotation of the coalescer is varied according toturbocharger efficiency. In a further embodiment, the speed of rotationof the coalescer is varied according to turbocharger boost pressure. Ina further embodiment, the speed of rotation of the coalescer is variedaccording to turbocharger boost ratio, which is the ratio of pressure atthe turbocharger outlet versus pressure at the turbocharger inlet. In afurther embodiment, the coalescer is driven to rotate by an electricmotor, e.g. 70, FIG. 3. In a further embodiment, the electric motor is avariable speed electric motor to vary the speed of rotation of thecoalescer. In another embodiment, the coalescer is hydraulically drivento rotate, FIG. 2. In a further embodiment, the speed of rotation of thecoalescer is hydraulically varied, FIG. 7.

The system provides a method for improving turbocharger efficiency in aturbocharger system 140 for an internal combustion engine 102 generatingblowby gas 104 in a crankcase 106, the system having an air intake duct108 having a first segment 142 supplying combustion air to aturbocharger 144, and a second segment 146 supplying turbochargedcombustion air from the turbocharger 144 to the engine 102, and having areturn duct 110 having a first segment 112 supplying the blowby gas 104to air-oil coalescer 114 to clean the blowby gas by coalescing oiltherefrom and outputting cleaned air at 116, the return duct having asecond segment 118 supplying the cleaned air from the coalescer 114 tothe first segment 142 of the air intake duct to join combustion airsupplied to turbocharger 144. The method includes variably controllingcoalescer 114 according to a given condition of at least one ofturbocharger 144 and engine 102. One embodiment variably controlscoalescer 114 according to a given condition of turbocharger 144. Afurther embodiment provides the coalescer as a rotating coalescer, asabove, and varies the speed of rotation of the coalescer according toturbocharger efficiency. A further method varies the speed of rotationof coalescer 114 according to turbocharger boost pressure. A furtherembodiment varies the speed of rotation of coalescer 114 according toturbocharger boost ratio, which is the ratio of pressure at theturbocharger outlet versus pressure at the turbocharger inlet.

FIG. 8 shows a control scheme for CCV implementation. At step 160,turbocharger efficiency is monitored, and if the turbo efficiency is okas determined at step 162, then rotor speed of the coalescing filterelement is reduced at step 164. If the turbocharger efficiency is notok, then engine duty cycle is checked at step 166, and if the engineduty cycle is severe then rotor speed is increased at step 168, and ifengine duty cycle is not severe then no action is taken as shown at step170.

FIG. 9 shows a control scheme for OCV implementation. Crankcase pressureis monitored at step 172, and if it is ok as determined at step 174 thenrotor speed is reduced at step 176, and if not ok then ambienttemperature is checked at step 178 and if less than 0 degree C., then atstep 180 rotor speed is increased to a maximum to increase warm gaspumping and increase oil-water slinging. If ambient temperature is notless than 0 degree C., then engine idling is checked at step 182, and ifthe engine is idling then at step 184 rotor speed is increased andmaintained, and if the engine is not idling, then at step 186 rotorspeed is increased to a maximum for five minutes.

The flow path through the coalescing filter assembly is from upstream todownstream, e.g. in FIG. 1 from inlet port 38 to outlet port 42, e.g. inFIG. 2 from inlet port 38 to outlet port 68, e.g. in FIG. 10 from inletport 190 to outlet port 192. There is further provided in FIG. 10 incombination a rotary cone stack separator 194 located in the flow pathand separating air from oil in the blowby gas. Cone stack separators areknown in the prior art. The direction of blowby gas flow through therotating cone stack separator is inside-out, as shown at arrows 196,FIGS. 10-12. Rotating cone stack separator 194 is upstream of rotatingcoalescer filter element 198. Rotating cone stack separator 194 is inhollow interior 200 of rotating coalescer filter element 198. In FIG.12, an annular shroud 202 is provided in hollow interior 200 and islocated radially between rotating cone stack separator 194 and rotatingcoalescer filter element 198 such that shroud 202 is downstream ofrotating cone stack separator 194 and upstream of rotating coalescerfilter element 198 and such that shroud 202 provides a collection anddrain surface 204 along which separated oil drains after separation bythe rotating cone stack separator, which oil drains as shown at droplet206 through drain hole 208, which oil then joins the oil separated bycoalescer 198 as shown at 210 and drains through main drain 212.

FIG. 13 shows a further embodiment and uses like reference numerals fromabove where appropriate to facilitate understanding. Rotating cone stackseparator 214 is downstream of rotating coalescer filter element 198.The direction of flow through rotating cone stack separator 214 isinside-out. Rotating cone stack separator 214 is located radiallyoutwardly of and circumscribes rotating coalescer filter element 198.

FIG. 14 shows another embodiment and uses like reference numerals fromabove where appropriate to facilitate understanding. Rotating cone stackseparator 216 is downstream of rotating coalescer filter element 198.The direction of flow through rotating cone stack separator 216 isoutside-in, as shown at arrows 218. Rotating coalescer filter element198 and rotating cone stack separator 216 rotate about a common axis 220and are axially adjacent each other. Blowby gas flows radially outwardlythrough rotating coalescer filter element 198 as shown at arrows 222then axially as shown at arrows 224 to rotating cone stack separator 216then radially inwardly as shown at arrows 218 through rotating conestack separator 216.

FIG. 15 shows another embodiment and uses like reference numerals fromabove where appropriate to facilitate understanding. A second annularrotating coalescer filter element 230 is provided in the noted flow pathfrom inlet 190 to outlet 192 and separates air from oil in the blowbygas. The direction of flow through second rotating coalescer filterelement 230 is outside-in as shown at arrow 232. Second rotatingcoalescer filter element 230 is downstream of first rotating coalescerelement 198. First and second rotating coalescer filter elements 198 and230 rotate about a common axis 234 and are axially adjacent each other.Blowby gas flows radially outwardly as shown at arrow 222 through firstrotating coalescer filter element 198 then axially as shown at arrow 236to second rotating coalescer filter element 230 then radially inwardlyas shown at arrow 232 through second rotating coalescer filter element230.

In various embodiments, the rotating cone stack separator may beperforated with a plurality of drain holes, e.g. 238, FIG. 13, allowingdrainage therethrough of separated oil.

FIG. 16 shows another embodiment and uses like reference numerals fromabove where appropriate to facilitate understanding. An annular shroud240 is provided along the exterior 242 of rotating coalescer filterelement 198 and radially outwardly thereof and downstream thereof suchthat shroud 240 provides a collection and drain surface 244 along whichseparated oil drains as shown at droplets 246 after coalescence byrotating coalescer filter element 198. Shroud 240 is a rotating shroudand may be part of the filter frame or end cap 248. Shroud 240circumscribes rotating coalescer filter element 198 and rotates about acommon axis 250 therewith. Shroud 240 is conical and tapers along aconical taper relative to the noted axis. Shroud 240 has an innersurface at 244 radially facing rotating coalescer filter element 198 andspaced therefrom by a radial gap 252 which increases as the shroudextends axially downwardly and along the noted conical taper. Innersurface 244 may have ribs such as 254, FIG. 17, circumferentially spacedtherearound and extending axially and along the noted conical taper andfacing rotating coalescer filter element 198 and providing channeleddrain paths such as 256 therealong guiding and draining separated oilflow therealong. Inner surface 244 extends axially downwardly along thenoted conical taper from a first upper axial end 258 to a second loweraxial end 260. Second axial end 260 is radially spaced from rotatingcoalescer filter element 198 by a radial gap greater than the radialspacing of first axial end 258 from rotating coalescer filter element198. In a further embodiment, second axial end 260 has a scalloped loweredge 262, also focusing and guiding oil drainage.

FIG. 18 shows a further embodiment and uses like reference numerals fromabove where appropriate to facilitate understanding. In lieu of lowerinlet 190, FIGS. 13-15, an upper inlet port 270 is provided, and a pairof possible or alternate outlet ports are shown at 272 and 274. Oildrainage through drain 212 may be provided through a one-way check valvesuch as 276 to drain hose 278, for return to the engine crankcase, asabove.

As above noted, the coalescer can be variably controlled according to agiven condition, which may be a given condition of at least one of theengine, the turbocharger, and the coalescer. In one embodiment, thenoted given condition is a given condition of the engine, as abovenoted. In another embodiment, the given condition is a given conditionof the turbocharger, as above noted. In another embodiment, the givencondition is a given condition of the coalescer. In a version of thisembodiment, the noted given condition is pressure drop across thecoalescer. In a version of this embodiment, the coalescer is a rotatingcoalescer, as above, and is driven at higher rotational speed whenpressure drop across the coalescer is above a predetermined threshold,to prevent accumulation of oil on the coalescer, e.g. along the innerperiphery thereof in the noted hollow interior, and to lower the notedpressure drop. FIG. 19 shows a control scheme wherein the pressure drop,dP, across the rotating coalescer is sensed, and monitored by the ECM(engine control module), at step 290, and then it is determined at step292 whether dP is above a certain value at low engine RPM, and if not,then rotational speed of the coalescer is kept the same at step 294, andif dP is above a certain value then the coalescer is rotated at a higherspeed at step 296 until dP drops down to a certain point. The notedgiven condition is pressure drop across the coalescer, and the notedpredetermined threshold is a predetermined pressure drop threshold.

In a further embodiment, the coalescer is an intermittently rotatingcoalescer having two modes of operation, and is in a first stationarymode when a given condition is below a predetermined threshold, and isin a second rotating mode when the given condition is above thepredetermined threshold, with hysteresis if desired. The firststationary mode provides energy efficiency and reduction of parasiticenergy loss. The second rotating mode provides enhanced separationefficiency removing oil from the air in the blowby gas. In oneembodiment, the given condition is engine speed, and the predeterminedthreshold is a predetermined engine speed threshold. In anotherembodiment, the given condition is pressure drop across the coalescer,and the predetermined threshold is a predetermined pressure dropthreshold. In another embodiment, the given condition is turbochargerefficiency, and the predetermined threshold is a predeterminedturbocharger efficiency threshold. In a further version, the givencondition is turbocharger boost pressure, and the predeterminedthreshold is a predetermined turbocharger boost pressure threshold. In afurther version, the given condition is turbocharger boost ratio, andthe predetermined threshold is a predetermined turbocharger boost ratiothreshold, where, as above noted, turbocharger boost ratio is the ratioof pressure at the turbocharger outlet vs. pressure at the turbochargerinlet. FIG. 20 shows a control scheme for an electrical version whereinengine RPM or coalescer pressure drop is sensed at step 298 andmonitored by the ECM at step 300 and then at step 302 if the RPM orpressure is above a threshold then rotation of the coalescer isinitiated at step 304, and if the RPM or pressure is not above thethreshold then the coalescer is left in the stationary mode at step 306.FIG. 21 shows a mechanical version and uses like reference numerals fromabove where appropriate to facilitate understanding. A check valve,spring or other mechanical component at step 308 senses RPM or pressureand the decision process is carried out at steps 302, 304, 306 as above.

The noted method for improving turbocharger efficiency includes variablycontrolling the coalescer according to a given condition of at least oneof the turbocharger, the engine, and the coalescer. One embodimentvariably controls the coalescer according to a given condition of theturbocharger. In one version, the coalescer is provided as a rotatingcoalescer, and the method includes varying the speed of rotation of thecoalescer according to turbocharger efficiency, and in anotherembodiment according to turbocharger boost pressure, and in anotherembodiment according to turbocharger boost ratio, as above noted. Afurther embodiment variably controls the coalescer according to a givencondition of the engine, and in a further embodiment according to enginespeed. In a further version, the coalescer is provided as a rotatingcoalescer, and the method involves varying the speed of rotation of thecoalescer according to engine speed. A further embodiment variablycontrols the coalescer according to a given condition of the coalescer,and in a further version according to pressure drop across thecoalescer. In a further version, the coalescer is provided as a rotatingcoalescer, and the method involves varying the speed of rotation of thecoalescer according to pressure drop across the coalescer. A furtherembodiment involves intermittently rotating the coalescer to have twomodes of operation including a first stationary mode and a secondrotating mode, as above.

Further development in the above technology including a magneticallydriven rotating separator and a rotating coalescer with keyed drive areprovided in commonly owned co-pending U.S. patent application Ser. No.13/167,814, filed Jun. 24, 2011, and U.S. patent application Ser. No.13/167,820, filed Jun. 24, 2011, all incorporated herein by reference.

Present Application

FIG. 22 shows a rotating separator 320 for separating liquid from afluid mixture. The separator assembly 322 includes a housing 324, and anannular rotating separating filter element 326, like element 28 above,rotating about an axis 328 extending along an axial direction (into thepage in FIG. 22) in the housing. Annular rotating separating filterelement 326 has an inner periphery 330 defining a hollow interior 332,and has an outer periphery 334. The housing has a sidewall 336 with aninner surface 338 facing outer periphery 334 of annular rotatingseparating filter element 326 and spaced along a radial direction 340radially outwardly of the annular rotating separating filter element bya plenum 342 therebetween. The housing has an inlet such as 38 in FIG. 1for supplying the fluid mixture to hollow interior 332, comparably asshown at arrows 40 in FIG. 1 supplying the mixture to hollow interior32. The housing has an outlet such as 42 in FIG. 1 delivering aseparated component of the mixture from plenum 342, comparably as shownat arrows 44 in FIG. 1 from plenum 36. The housing has a drain such as54 in FIG. 1 delivering separated liquid from the plenum, comparably asshown at arrows 50, 52 in FIG. 1. The direction of flow through theannular rotating separating filter element is inside-out as shown atarrow 340 from hollow interior 332 through annular rotating separatingfilter element 326 to plenum 342. Separating filter element 326 isrotated for example by axially extending shaft 58 as in FIG. 1 or othersuitable drive mechanism including as noted above. The structuredescribed thus far is as noted above.

In the present disclosure, the noted plenum has one or more flow pathseparating guides 350 minimizing the flow of separated liquid to theoutlet, and guiding the separated liquid toward the drain. In oneembodiment, the one or more flow path separating guides are provided byone or more fins 352, FIG. 23, extending into plenum 342 from innersurface 338 of the sidewall 336 of the housing. The fins are arcuatelyspaced from each other along inner surface 338 of sidewall 336 of thehousing. The fins create capture grooves 354 catching the liquid, asshown at coalesced liquid droplets 356. The fins are tilted or slantedinto the flow path of liquid exiting from annular rotating separatingfilter element 326, whose direction of rotation is shown at arrow 358.The tangential swirl flow of the liquid is shown at arrows 360, and thecentrifugal flung-out flow of the liquid into capture grooves 354 isshown at arrows 362. Each fin extends from a root end 364 at innersurface 338 of sidewall 336 of the housing to a distal tip end 366 inplenum 342 pointing in a direction opposite to the direction of rotation358 of annular rotating separating filter element 326 such that fins 352and inner surface 338 of sidewall 336 of the housing form wedge-shapecavity 354 catching separated liquid 356. Fins 352 extend obliquelyrelative to radial direction 340.

In one embodiment, FIG. 24, the drain 370 is provided at a lower portion372 of plenum 342, and the outlet 374 is provided at an upper portion376 of plenum 342. In this embodiment, the inlet 378 is provided at thebottom of hollow interior 332 of annular rotating separating filterelement 326. In another embodiment, the inlet, outlet and drain areprovided as shown above in FIG. 1+.

Fins 352 define one or more guide surfaces guiding separating liquidalong a drain direction toward the drain. In one embodiment, the draindirection is normal to radial direction 340. In another embodiment, thedrain direction is also tangential to radial direction 340. In oneembodiment, fins 352 wind helically downwardly toward the drain, forexample as shown in FIG. 25 with a plurality of closely verticallyspaced fins 380 forming capture grooves 382 therebetween and helicallywinding downwardly around the inner circumference of inner surface 338of the housing sidewall, to guide the captured coalesced liquid droplets356 in a spiral pattern downwardly to the bottom of plenum 342 at lowerportion 372 to drain at drain 370. FIG. 26 shows another helical patternfor fins 384 on inner surface 338 of housing sidewall 336, which fins384 have greater vertical spacing than in FIG. 25 and provide ledges orramps 386 for the liquid to flow spirally downwardly therealong to lowerportion 372 of plenum 342. In a further embodiment, FIG. 27, helicallywound fins 384 have one or more axially extending slots 388 formedtherethrough for gravitational drainage of separated liquid through therespective slot. The fins 352 of FIG. 23 may wind helically along innersurface 338 of sidewall 336, or may extend axially downwardly therealongin rectilinear manner, or may have other curved configuration to guideand aid drainage of separated liquid therealong.

In one embodiment, the sidewall of the housing tapers away from the axisof rotation 328, for example as shown in FIG. 28 at tapering housingsidewall 336 a. Sidewall 336 a tapers away from annular rotatingseparating filter element 326 as sidewall 336 a extends away from upperportion 376 of plenum 342 and toward lower portion 372 of plenum 342.The one or more flow path guides provided by the noted fins creategreater swirl in the plenum closer to upper portion 376 of the plenumand lesser swirl in the plenum closer to lower portion 372 of theplenum, to aid drainage of separated liquid toward lower portion 372 andaway from upper portion 376, and less entrainment of separated liquid inthe swirl. As the separated liquid flows helically downwardly along thefins, for example fins 384 of FIG. 26, the cumulative liquid flow andvolume of fluid is greater at the lower portion 372 of the plenum thanat the upper portion 376, and hence it may be desired to lessen swirlvelocity at the lower portion 372 of the plenum to reduce entrainment ofthe greater volume of liquid available thereat as such liquid flowshelically downwardly along the fins. Typical rotational speed of annularrotating separating filter element 326 may be approximately 3,000 rpm,thus resulting in significant tangential velocity of the outer periphery334 of the annular rotating separating filter element 326 and concordantexit swirl velocity of coalesced liquid droplets 356 as they leave outerperiphery 334 and enter plenum 342, as well as the swirl velocity of theremaining component or components of the mixture, such as air in theabove noted crankcase ventilation separator, thus also causingsignificant air swirl velocity, which swirl may re-entrain the separatedliquid. The outward tapering of sidewall 336 a provides greater plenumvolume at lower portion 372, and thus reduced swirl velocity.

In another embodiment, the noted one or more flow path separating guidesare configured to create a tortuous path in plenum 342. In oneembodiment, the one or more flow path separating guides are provided byone or more swirl flow dampers such as 390, FIG. 29, in the plenum.Swirl flow damper 390 is at upper portion 376 of plenum 342. In oneembodiment, a plurality of swirl flow dampers such as 390 are providedin plenum 342. In one embodiment, the swirl flow damper is adjacentinner surface 338 of sidewall 336 of the housing. In one embodiment, theswirl flow damper is upstream of outlet 374. In one embodiment, swirlflow damper 390 is a vortex tube. In one embodiment, the one or moreflow path separating guides are configured to break down secondary flowin plenum 342, and create low shear recirculation zones such as 392,FIG. 25, 394, FIG. 29, for collection of separated liquid.

In further embodiments, the one or more flow path separating guides,e.g. fins 352, 380, 384, are liquid-phobic, i.e. liquid-repelling, toaid drainage therealong of the separated liquid. In one embodiment, foruse in an internal combustion engine crankcase ventilation separator,the noted one or more flow path separating guides, e.g. the fins, areoleophobic.

In another embodiment, the noted one more flow path guides are providedby a configured inner surface 338 a, FIG. 30, of sidewall 336 of thehousing. In one embodiment, a media layer 396 provides the notedconfigured inner surface of sidewall 336 of the housing. In oneembodiment, media layer 396 includes at least fibrous media layer. Inone embodiment, media layer 396 includes at least one non-woven fibrousmedia layer. In one embodiment, media layer 396 includes at least onewoven screen. In one embodiment, media layer 396 includes at least onewire mesh layer. In one embodiment, media layer 396 includes arestrictive wrap. In one embodiment, the noted configured inner surfaceof the sidewall of the housing is liquid-philic, i.e. liquid-attractive.This may be desired in embodiments with or without fins 352, 380, 384,or swirl flow damper 390, where it is desired to retain the separatedliquid at the inner surface of sidewall 336 of the housing and minimizere-entrainment in the swirl therepast. The liquid-philic inner surfaceof sidewall 336 may be used in combination with fins such as 384 orswirl flow dampers such as 390. For example in FIG. 26, the fins 384,particularly along ramps or ledges 386, may be liquid-phobic, while theinner surface of the sidewall therebetween, e.g. 338 a, may beliquid-philic. The liquid-philic inner surface 338 a of sidewall 336,which may or may not be provided by a liquid-philic media layer 396, maybe used with or without the noted fins and with or without the notedswirl flow dampers. In one embodiment, for use in an internal combustionengine crankcase ventilation separator, media layer 396 is oleophilic.

In one embodiment, the disclosed rotating separator is an internalcombustion engine crankcase ventilation rotating separator separatingoil from air in blowby gas from the crankcase, with the inlet supplyingblowby gas from the crankcase to hollow interior 332, the outletdelivering cleaned separated air from plenum 342, and the drain drainingseparated oil from plenum 342. In one embodiment, the noted fluidmixture is a gas-liquid mixture. In one embodiment, the noted fluidmixture is a liquid-liquid mixture including a first liquid separatedfrom the mixture and drained to the drain, and a remaining liquidsupplied to the outlet. In one embodiment, the rotating separator is afuel-water separator, with the water being the noted first liquid, andthe fuel being the noted remaining liquid.

In the foregoing description, certain terms have been used for brevity,clearness, and understanding. No unnecessary limitations are to beinferred therefrom beyond the requirement of the prior art because suchterms are used for descriptive purposes and are intended to be broadlyconstrued. The different configurations, systems, and method stepsdescribed herein may be used alone or in combination with otherconfigurations, systems and method steps. It is to be expected thatvarious equivalents, alternatives and modifications are possible withinthe scope of the appended claims. Each limitation in the appended claimsis intended to invoke interpretation under 35 U.S.C. .sctn. 112, sixthparagraph, only if the terms “means for” or “step for” are explicitlyrecited in the respective limitation.

What is claimed is:
 1. A rotating separator for separating liquid from afluid mixture, the rotating separator comprising: a housing having asidewall with an inner surface; a first annular rotating separatingfilter element positioned within the housing and centered about an axisextending along an axial direction in the housing, the first annularrotating separating filter element having a first inner peripherydefining a first hollow interior, and having a first outer peripheryfacing the inner surface of the housing and spaced along a radialdirection radially outwardly from the inner surface thereby defining afirst portion of a plenum therebetween; a second annular rotatingseparating filter element positioned within the housing and centeredabout the axis, the second annular rotating separating filter elementhaving a second inner periphery defining a second hollow interior, andhaving a second outer periphery facing the inner surface of the housingand spaced along a radial direction radially outwardly from the innersurface thereby defining a second portion of the plenum therebetween;and the housing including an inlet for supplying the mixture to thefirst hollow interior, an outlet delivering a separated component of themixture from second hollow interior, and a drain delivering separatedliquid from the plenum.
 2. The rotating separator of claim 1, whereinthe first annular rotating separating filter element and second annularrotating separating filter element are adjacent to each other.
 3. Therotating separator of claim 1, wherein the first hollow interior and thesecond hollow interior are separated by a divider.
 4. The rotatingseparator of claim 3, wherein the divider is positioned between thefirst annular rotating separating filter element and second annularrotating separating filter element.
 5. The rotating separator of claim1, wherein the first annular rotating separating filter element andsecond annular rotating separating filter element are configured to berotated about the axis.
 6. The rotating separator of claim 1, whereinthe fluid mixture flows along a flow path through the housing, the flowpath directing the mixture through the first annular rotating separatingfilter element in an inside-out manner from the hollow interior throughthe first annular rotating separating filter element into the plenum. 7.The rotating separator of claim 6, wherein the flow path directing themixture through the second rotating separating filter element in anoutside-in manner from the plenum through the second annular rotatingseparating filter element.